In the case of infusion to a patient or the like occasion, an indwelling needle connected to an infusion line is stuck into a blood vessel of the patient and indwells there.
Such an indwelling needle includes a hollow outer needle, an outer needle hub fixed to the base of the outer needle, an inner needle having a sharp point at its tip and inserted into the outer needle, and an inner needle hub fixed to the base of the inner needle.
At the time of puncturing a patient's blood vessel with the indwelling needle, the inner needle is inserted into the outer needle, the needle point of the inner needle is protruded from the tip of the outer needle, and, in this assembled condition, the puncturing operation is carried out.
Then, when the needle point of the inner needle has reached the inside of the blood vessel, the blood flowing in through the opening at the needle point passes through the inner cavity of the inner needle, and flows into the inside of the transparent inner needle hub (flush-back). This makes it possible to confirm (visually check) that the inner needle has captured the blood vessel.
After confirmation of the flush-back, the inner needle and the outer needle are slightly moved forwards to insert the tip of the outer needle into the blood vessel.
Next, while gripping the outer needle by hand, the inner needle is pulled out of the outer needle, and a connector of the infusion line is connected to the outer needle hub. Then, an infusion liquid is infused through the connected infusion line and the outer needle.
Meanwhile, at the time of pulling off the outer needle from the inner needle, it is necessary to hold the conduit of the outer needle in a closed state, for preventing the blood from flowing out through the base of the outer needle hub. This is a very troublesome operation.
As a solution to such a problem, for example, Japanese Laid-Open Patent Publication No. 10-179734 discloses an indwelling needle. A tube of an infusion line or the like is preliminarily connected to an outer needle hub.
In this indwelling needle, however, the tube is connected to a lateral side of the outer needle hub, and, therefore, the tube serves as an obstacle at the time of the puncturing operation, leading to poor operationality.